Electric metering system.



W. H. PRATT. ELECTRIC METERING SYSTEM.

APPLIOATION FILED FEB. 9, 1903.

PATENTED JULY 17, 1906.

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W. H. PRATT. ELECTRIC METERING SYSTEM.

APPLICATION FILED FEB.9, 1903.

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(Di I Ham 'Hbhatb, y J/ M aqtty witnesses /Z W. H. PRATT. ELECTRICMETERING SYSTEM.

APPLICATION FILED FEB.9,1903.

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PATENTED JULY 17, 1906. W.,H. PRATT. ELECTRIC METERING SYSTEM.

APPLICATION FILED PEB.9,1903.

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witnesses: IrwQenLor; it/ ClJilHam 'Hpbatt, X y fi M M AW 'No. 826,272.PATENTED JULY 17, 1906.

W. H. PRATT.

ELECTRIC? METERING SYSTEM. APPLICATION FILED PEB.9.1903.

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witnesses: IrwOenboh (DH HamHDbaLb PATENTED JULY 17, 1906.

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b, y @H mm W 3 mi UNITED TES PATENT OFFICE.

WILLIAM H. PRATT, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

ELECTRIC METERING SYSTEM- Specification of Letters Patent.

Application filed February 9, 1903. Serial No.142,447.

To all whom it may concern:

Be it known that I, WILLIAM H. PRATT, a citizen of the United States,residing at Lynn, county of Essex, State of Massachusetts, have inventedcertain new and useful Improvements in Electric Metering Systems, ofwhich the following is a specification.

My invention relates to means for controlling electric meters, ahd isintended more especially for use in connection with a meter or meters ofa type provided with two registering or recording devices, one of whichis to be thrown in circuit under certain conditions of operation and tobe replaced by the other under certain other conditions of operation.Thus, for example, my invention is useful in cases where it is desiredto measure the energy flowing in the circuit of a dynamoelectric machinewhich operates sometimes as a generator and at other times as a motor. Ameter or meters used in this connection record on one dial or registerthe energy flowing when the machine is a enerator and on the other dialthe energy owing when the machine acts as a motor. To throw theregisters or counters into and out of operation, I employ a magneticdevice controlled by a relay of a construction responsive to reversal ofcurrent in the mains of the system to which the meter or meters areconnected.

The features ofnovelty which characterize my invention I have pointedout with particularity in the ap ended claims, while the inventionitself, bot as to the details of construction and mode of operation ofone of the many embodiments of which it is capable, I have set forthmore at length in the following description, which is to be taken inconnection with the accompanying drawings, in which- Figure 1 representstwo meters of the Thomson recording-wattmeter type, arranged for use inconnection with a three-phase alternating-current system and providedwith a polyphase relay for controlling the counters or registers of eachof the meters. Figs. 2, 3 4, 5, and 6 are various views showing themechanism for throwing the counters or registers of a meter into and outof operative connection to'the movable member of the meter by which thecounters are driven. Figs. :7, 8, and 9 are detail views of the contactmaking andbreaking devices forming a portion of the polyphase relayshown in the middle portion of Fig. 1, while Fig. 10 is a diagram ofcircuits of a system arranged according to my invention.

The metering system to which I have chosen to apply my invention,consists in the present instance of two recording-wattmeters of theThomson type, the construction of which is well understood in the art.The current-coils of one instrument receive current from one of thethree mains of a threephase system the energy of which is to bemeasured, while the current-coils of the second instrument receivecurrent from another of the mains of said system. The potentialcoils ofthe instruments receive current from between the third main and thefirst-mentioned mains. The particular method of connecting up the metersor instruments so that their readings represent the ower consumed in thethree-phase circuit orms, however, no part of the present invention.

The meters to which I have referred are represented in Fig.1, one at theleft-hand portion of the figure at l with its glass cover broken away soas to show the working parts and the other at the right of the figure at2 with only such portions of the lass cover broken away as to show thetwo ials 3 4 of the counting or registering mechanism, which in thiscase is of the well-known cyclometer t pe.

The details of the cyclometer registering mechanism are shown perhapsmore clearly in the plan view in Fig. 4, in which the counting-disks ofone c y'clometer-register are indicated at 5 and the counting-disks ofthe companion register 'at 6. A magnetically-actuated pivoted lever 7serves when thrown into one of its extreme positions to connect one ofthe counters into operative relation with the vertical shaft 8 of themeter, the upper end of which carries a worm 8, as shown in Fig. 3,which engages a train of gear-wheels for driving the counters, as willbe readily understood by reference to Figs. 3 and 6.

The particular means whereby the respective counters are thrown into orout of gear with the driving member of a meter is shown perhaps best inFig. 5, though certain of the features of the same are represented "inother figures as well. The electromagnetically-actuated rod 7 shown inplan view in Fig. 4 is indicated in cross-section at 7 in Fig. 5. Itwill be seen that when this pivoted rod is thrown to the left it engagesone of the two collars 9 and. 10 on the sliding rod 11, thereby oerating to throw this rod in its bearings, an so correspondingly movingthe two pivoted levers 12 and 13, which immediately control sets ofmechanism whereby the counters of the meter are thrown into or out ofear. the sli ing rod 11 to the levers 12 and 13 through theinstrumentality of pairs of collars or rings 14 15, between the membersof which loosely play the upper ends of the levers 12 and 13, asindicated. These levers are pivoted to any suitable portion of theapparatus-as, for example, to posts 16 17. The lower end of each of thelevers 12 13 operates a clutching mechanism. The lower end of lever 12,for example, plays between. the walls of a constricted portion of asleeve 18, mounted upon a shaft 19, by which it 1 is adapted to beturned. A spring 20, acting against a collar-21 on the shaft 19, pushesthe sleeve 18, when permitted to do so, against a gear-wheel 22, looselymounted on the shaft 19. This gear-wheel 22 is driven from a shaft 23,which receives its motion from another gear-wheel 24; which meshes witha worm 8, carried by the armatureshaft of the meter. When the lever-arm7 is -moved so as to throw the lower end of the lever 12 to the left,the spring is released, thereby ressing the friction-disk 25, formed onthe s eeve 18, against the gear 22, which thereupon communicates motionto the shaft 19, which motion in turn is transmitted through the pinion26, and so on to the count1ngwheels of the 'cyclometer-register, as willbe seen more clearly by reference to Fig. 6.

The clutching mechanism for the other register is shown at the right ofFig. 5 and is the same in construction as that shown at the left of thefigure. In the figure, however, the clutching mechanism at the right isshown in a position in which the gear-wheel 27, corresponding to thegear-wheel 26 of the mechanism at the left of the figure, is inclutching relation to the shaft 28 instead of in the unclutched or disenaged position in which the gear 22 at the left of the figure is shown.It will be understood that when the lever 7 is thrown so as to shift theshaft 11 toward the right the mechanism at the right of the figure willbe unclutched, while that at the left will be thrown into operativeengagement, as already described.

The electromagnetic means for actuating the clutch-throwing lever 7consists of two electroma nets 29 and 30. (Shownin side elevation in ig.2 and in plan view in Fig. 4.) These magnets are provided with pivotedarmatures 31 and 32, respectively. The upper ends of these armatures areconnected by a Motion is communicated from cross-bar 33, which carriestwo circuit-closing contacts 34 and 35. Motion is communicated to theclutch-throwing lever 7 by means of pins 36, between which the free endof the lever 7 loosely plays.

The contact 34 operates in conjunction with the polyphase relay, towhich reference has already been made, to control the circuits of theactuatingmagnets 29 and 30, while the other contact 35 operates whenshifted to throw out of circuit one and into circuit another of twostarting-coils on each meter, one of which starting-coils operates whenthe meter runs in one direction and the other when the meter operates inthe oppo site direction. The functions of the contacts 34 and 35, which,together with their 006 erating fixed contacts, are clearly shown in ig.4, will be better understood by reference to the diagram of circuits inFig. 10. In this figure the polyphase relay is repre senteddiagrammatically at the upper righthand corner of the figure. Thisrelay, as will be seen, is similar in construction to an ordinarypolyphase induction-meter. It is provided with a shaft 37, carrying adisk 38, operated upon by two pairs of motor elements, each of whichconsists of a current coil or coils and a potential-coil.

In Fi 1 the current-carrying coils of one motor e ement are indicated at39, and the U-shaped core carrying the potential-coil is represented at41. Unlike an inductionmeter, however, this instrument has no dampingmagnets and no counter or register. Instead ofv actuating a counter orregister the shaft 37 carries a circuit-closing contact 44, (indicatedin detail in Figs. 7, 8, and 9.) This contact 44 is fixed rigidly to theshaft 37 and receives its currents through a spiral spring, as shown. Itcooperates with two resiliently-mounted, contacts 46 and 48. Mechanicalstops 45 and 47, cooperating with an arm 43 on the shaft 37 serve tolimit the angular movement of the shaft and prevent undue forcebeingexerted upon the delicately-mounted contacts 46 and 48.

The connections afiorded by the cooperating contacts above described areindicated in Fig. 10, in which it will be seen that the movable memberof the relay is in one of its extreme positions. In this position theconductor 49 is supposed to be connected to the conductor 50 anddisconnected from the conductor 51.

Before proceeding to a detailed description of the effect of theconnections made by the relay it will perhaps be best to describe in ageneral way the system shown in Fig. 11). In this figure the mains ofthe three-phase system, the energy flowing in which is to be measured,are indicated at 52, 53, and 54. The current-coils of the meters insteadof being connected directly in series with the particular mains of thethree-phase system seem are connected indirectly through the secondarycoils of current-transformers. In Fig. 10 one meter only and itscircuits are indicated. For the sake of clearness the other meter andits connections are omitted; but the terminals therefor are shown at 55,and these terminals are connected with circuits of the meter in the samemanner as the set of terminals for the meter shown at the left of thefigure. It will be seen that one terminal of the secondary of thecurrent-transformer 56 is connected in circuit through the currentcoils57 of the meter shown, then through the current coil or coils 58 of oneof ,the motor elements of the polyphase relay, and thence back to theother terminal of the secondary of the transformer 56. Thepotential-circuit of the meter is supplied from the secondary of thepotential-transformer 59, the primary of which is connected between themains 52 and 53. The potential circuit or secondary of the transformer59 has two distinct branches, one'of which consists of the leads 60,which, as will be seen, supply the potential-current to thepotential-coils 61, corresponding to the current-coil 58, both of whichtogether constitute one of the motor elements of the polyphase relay.The other branch of the potential circuit extends from the secondary ofthe transformer 59, one lead passing to the armature 61 and then to themovable contact 35, which when in the position shown completes thecircuit through the fixed contact 62 and through the startingcoil 63 tothe other branch or terminal of the secondary of the transformer 59.When in its other position,'the contact 35, coeperating with the otherfixed contact 64, completes the potential-circuit through the otherstarting-coil 65 the starting-coil 63 being then of course cut out ofcircuit.

The magnets 29 and 30, which are shown as actually constructed in Fig. 2and in diagram in Fig. 10, are controlled by the polyphase relay in amanner now to be described and receive their energy from any suitablesource, in the present instance from the secondary of thepotential-transformer 66, used for supplying the otential-current to themeter supposed to e connected to the terminals 55, which meter, asbefore mentioned, is for the sake of preventing undue complication notshown in the drawings.

Let it be supposed that energy is flowing in the polyphase mains in sucha direction that the movable element of the relay is turned into theposition shown and that in this position the lead 49 is connected to thelead 50. The result of this connection is to complete a circuit from theterminal 67 of the potentialtransformer 66 through the magnet 30 andback to the other terminal of the transformer, as will be readily seen.The armature carrying the contacts 34 and 35 is immediately moved to theright, thereby opening the circuit of the magnet 30 as the contact 34moves out of engagement with the contacts 68, bridged thereby, andclosing one of the breaks in the circuit of the magnet 29 by bridgingthe contacts 69, whereby the magnet 29 is in a condition to be energizedas soon as the relay moves into a position the opposite of that shown,and thus completes the circuit.

Simultaneously with the breaking of the circuit of the magnet 30,thereby relieving the contacts of the relay of this duty, the contact 35cuts out of circuit the starting-coil 63 and into circuit thestarting-coil 65, the latter coil operating to assist the meter in itsnew direction of rotation.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is'

1. The combination of a meter, the two starting-coils therefor, one foruse when the meter rotates in one direction and the other for use whenthe meter rotates in the opposite direction, two counters or registeringdevices, and means controlled by the direction of flow of energy in themeter-circuit for putting into operation one of the counters and one ofthe starting-coils when the meter rotates in one direction and forsubstituting the other counter and the other starting-coil when themeter reverses its direction of rotation.

2. The combination of a polyphase alternating-current system, meters formeasuring the energy flowing in said system, each of said meters beingprovided with two counters or registering devices, one of which isadapted for use when the meter rotates in one direction and the otherfor use when the meter rotates in the opposite direction, and apolyphase relay operating upon each meter to substitute one counter orregistering de vice for the other when the fiow of energy in thepolyphase system reverses.

3. A polyphase rela consisting of a rotatable member, a plura ity ofmotor elements acting uponsaid member, and circuit-controlling meansoperating upon the movement of the member in one direction to completethe given circuit and to close another circuit when moving in theopposite direction.

4. The combination of an alternating-current system, a meter connectedthereto, two counters or registering devices for the meter, twostarting-coils for the meter, electromagnetic means for disconnectingone counter and one starting-coil and replacing them by the othercounter and starting-coil, and an alternating-current relay device forcontrolling said electromagnetic means.

5. The combination of a meter, a plurality of counters or registeringdevices therefor, a plurality of starting-coils therefor, and meansoperative in response to reversal of the meter for throwing both acounter or registering device and a starting-coil out of operation andanother counter and another starting-coil into operation.

6. The combination of a meter, two registering devices, one forregistering the revolutions of the meter in one direction and the otherfor registering the revolutions in the opposite direction, a pluralityof startingcoils, and means external to the meter for controlling theoperation of the starting-coils and registering devices. 10

In witness whereof I have hereunto set my hand this 2d day of February,1903.

WILLIAM H. PRATT. Witnesses:

DUGALD MoK. MCKILLOP, ROBERT SHAND.

